The project shows you how to build a simple temperature alarm with PIC16C84 microcontroller and a 2-line LCD display. It can be used as a temperature alarm or a thermostat – the only difference being that with an alarm an intermittent beep is produced when a limit is exceeded.
The project comes with 3-key keypad which allows the user to set independent high and low temperature alarm points. It can display current temperature in both Celsius and Fahrenheit degrees. The alarm also records the minimum and maximum temperatures encountered.
Project Firmware, Schematic and Documentation